Coral recruit size-escape thresholds under fish grazing

Algae covered tiles containing week-old and month-old coral recruits of Acropora millepora, Acropora kenti and Goniastrea retiformis were exposed to different types of fish grazing to investigate the impact of grazing on coral recruit survival. High resolution images of tiles where used to track recruit size and survival, and algae coverage, pre and post 24 hour exposure to fish grazing. The tested fish grazers were Ctenochaetus binotatus (a 'brusher'), Salarias fasciatus ('brusher'), Acanthurus nigrofuscus ('cropper') and Zebrasoma scopas ('concealed cropper'); also included were a 'control' treatment where tiles were undisturbed for the 24 hours and a 'manual' treatment where algae was removed by an aquarist. After the experiment, fish were anaesthetised and measured. These data were collected in December 2023.